Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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Opal-AN from
Biermann Quarries (Bethel quarries; Codfish Hill Quarry), Bethel, Fairfield County, Connecticut, USA


Locality type:Quarry
Classification
Species:Opal var: Opal-AN
Formula:SiO2 · nH2O
Formation:Secondary
Comments:Minor coatings on fracture surfaces, nearly impossible to see without using a UV lamp.
Habit:coatings
Colour:colorless
Luminescent properties:bright green under SW UV
Quality for species:Poor for species, only of interest for locality collectors. (#)
Confirmation
Validity:Confirmed
Confirmation Methods:Visual (Fluorescence)
Data
Mineral Data:Click here to view Opal-AN data
Locality Data:Click here to view Biermann Quarries (Bethel quarries; Codfish Hill Quarry), Bethel, Fairfield County, Connecticut, USA
Data Identifiers
Mindat Occurrence Record ID:130930
Long-form Identifier:1:3:130930:0
GUID (UUID V4):0
Nearest other occurrences of Opal-AN
8.1km (5.0 miles) ⓘSky Ridge railroad cut, Hawleyville, Newtown, Fairfield County, Connecticut, USA
10.9km (6.8 miles) ⓘNorth Street mall, Danbury, Fairfield County, Connecticut, USA
11.4km (7.1 miles) ⓘU. S. Route 7 Expressway (Danbury line to Iron Works District), Brookfield, Fairfield County, Connecticut, USA
12.1km (7.5 miles) ⓘFillow Quarry, Branchville, Redding, Fairfield County, Connecticut, USA
12.2km (7.6 miles) ⓘOld Mine Plaza construction site, Long Hill, Trumbull, Fairfield County, Connecticut, USA
12.6km (7.8 miles) ⓘOld Mine Park (Old Tungsten Mine), Long Hill, Trumbull, Fairfield County, Connecticut, USA
12.8km (8.0 miles) ⓘWestern Connecticut State University, Danbury, Fairfield County, Connecticut, USA
15.4km (9.6 miles) ⓘCasey Quarry (Ridgefield pegmatite), Ridgefield, Fairfield County, Connecticut, USA
18.1km (11.2 miles) ⓘCurtis Quarry, Southford, Southbury, New Haven County, Connecticut, USA
23.4km (14.5 miles) ⓘInterstate 84 road cuts, Town of Southeast, Putnam County, New York, USA
References
Januzzi, Ron E., Seaman, David M. (1976) Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut, USA.
 
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